1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
use v5.10;
use warnings;
my $calculator = do{
use Regexp::Grammars;
qr{
<Answer>
<rule: Answer>
<X=Mult> <Op=([+-])> <Y=Answer>
| <MATCH=Mult>
<rule: Mult>
<X=Pow> <Op=([*/%])> <Y=Mult>
| <MATCH=Pow>
<rule: Pow>
<X=Term> <Op=(\^)> <Y=Pow>
| <MATCH=Term>
<rule: Term>
<MATCH=Literal>
| <Sign=([-+])> \( <Answer> \)
| \( <MATCH=Answer> \)
<token: Literal>
<MATCH=( [+-]? \d++ (?: \. \d++ )?+ )>
}xms
};
while (my $input = <>) {
if ($input =~ $calculator) {
use Data::Dumper 'Dumper';
warn Dumper \%/;
}
}
|
